This invention relates to a flushing apparatus and more specifically to a novel and more reliable device for unclogging and cleaning various types of drain pipes.
It is the primary object of this invention to provide a device for removing obstructions from drain pipes having an expansible member which, after its insertion into the drain pipe, may be expanded by a fluid under pressure to provide a fluid tight joint between the expansible member and the inner surface of the pipe to enable fluid under sufficient pressure to be injected between the expansible member and the obstruction to force the obstruction from the pipe.
The prior art structure in this area of which applicant is aware is exemplified, for example, in U.S. Pat. No. 3,075,535 which discloses a device for unclogging drains having an expansible chamber and a single four position valve of complex costly construction. In the first position of the valve, the expansible chamber is filled with water under pressure to expand same against the inner surface of the obstructed pipe. Rotation of the valve to the second position closes off water pressure to the expansible chamber and further rotation of the valve to the third position introduces water under pressure between the obstruction and the expansible chamber for forcing the obstruction from the pipe. The fourth position drains the water from the expansible chamber into the unobstructed pipe. If the obstruction is loosely held in the pipe, such prior art devices work fairly satisfactorily. However, if the obstruction is firmly held, the continued flow of water under pressure in the area between the obstruction and the expansible chamber builds to the point where the expansible chamber is deformed causing the pressurized water to escape around the sides thereof or the expulsion of the expansible chamber from the pipe with the obstruction remaining in place.
The present invention overcomes the aforedescribed disadvantages of the prior art by providing a flushing apparatus which utilizes separate and independent valves, one valve of which controls the flow of fluid under pressure to the expansible chamber, the other valve controls the flow of pressurized fluid to the area between the obstruction and the expansible chamber for removing the obstruction. Thus, in applicant's apparatus, if the obstruction is firmly held, fluid pressure can be increased in the expansible chamber by the valve associated therewith to increase the chamber's frictional hold on the inside wall of the pipe while at the same time fluid under sufficient pressure can be introduced through the other valve to dislodge the obstruction. With applicant's device, no leakage of fluid past or expulsion of the expansible chamber will result as is possible with the prior art devices. In order to ensure that the designed burst limit of applicant's expansible chamber is not exceeded, a pressure regulator may be installed in the fluid supply line leading thereto. In addition, applicant's use of a simple commercially available device housing both valves substantially reduces the overall cost below that associated with the devices of the prior art.
It is therefore a further primary object of the present invention to provide a superior as well as novel apparatus for removing more difficult obstructions from drain pipes than are capable with the devices of the prior art.
It is another object of the present invention to provide an apparatus for the purpose described which is manually controlled and does not require any particular skill or knowledge in its operation.
It is a further object of the present invention to provide a device for the described purpose which is efficient, durable and economical to make, use and maintain.
These and other objects and advantages of the invention will become apparent upon reference to the following specification, attendant claims and drawing.